The cultivation of propagating microorganisms by providing the proper nutritional and environmental conditions is well known. In general, the contributing factors for suitable propagating conditions include the nature and level of nutrients provided in the growth media, pH, temperature, and aeration. Other factors which must be controlled include the salt concentration and osmotic pressure of the medium and in some cases, such special factors as light for photosynthetic organisms.
A suitable growth medium must contain all the nutrients required by the microorganism which is to be cultivated. In general, the following nutrients must be provided:
(1) hydrogen donors and acceptors; PA1 (2) a carbon source; PA1 (3) a nitrogen source; PA1 (4) minerals, such as sulphur and phosphorous and trace elements such as potassium, magnesium, calcium and iron.
In addition, it is known that certain growth factors are required. A growth factor is an organic compound which a microorganism must contain in order to grow but which is unable to synthesize. Many microorganisms, when provided with the nutrients listed above, are able to synthesize all of the organic constituents of their protoplasm, including amino acids, vitamins, purines and pyrimadines, fatty acids and other compounds. Each of these essential compounds is synthesized by a discrete sequence of enzymatic reactions and each enzyme is produced under the control of a specific gene. When an organism undergoes a gene mutation resulting in failure of one of these enzymes to function, the chain is broken and the end product is no longer produced. The microorganism must then obtain that compound from the environment and the compound has become a growth factor for the organism.
U.S. Pat. No. 3,293,145 to Leavitt describes a method for increasing the growth rate of achromobacter and Nocardia, comprising incubating the microorganisms in the presence of oxygen and an aliphatic hydrocarbon such as polyoxyethylene stearate, as the sole source of carbon for energy and growth. The hydrocarbon is added to an aqueous mineral salt solution which includes 0.015 to 10% of urea, 0.01 to 10% of a water soluble inorganic ammonium salt and 0.001 to 5% of a nonionic surface active agent.
Different microorganisms vary widely in their nutritional and growth factor requirements. The present invention is directed to the provision of a substance which enhances the growth rate and amount of growth of mycobacteria in a growth medium containing nutrients required for their growth.